Improvement in low-water indioatoe



THEODOR G. EISWALD, OF PROVIDENCE, RHODE ISLAND.

Letters Patent No. 80,400, dated July 28, 1868.

IMPROVEMENT IN LOW-WATER INDIGA-IOR.

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TO ALL WHOM IT MAY CONCERN:

Be it known *that I, THEODOR G. EISWALD, of the city and county of Providence, ,and State of Rhode ,Island, have invented a new and improved Combined Low-Water Indicator and Try-Cock; and I do hereby declare that the-following is a full, clear, and exact description of the construction and operation of the same, reference being had to the accompanying drawings, making apart of this specification, in which- 0 Figure 1 is atop view. i i

Figure 2 is a longitudinal vertical section. This invention relates to that class of low-Water indicators in which a fusibleplug is employed, and consists in a simple and convenient device by which the interior of such indicators can be kept cleanfrom the accumulation of dirt, sediment, or scale, and by which, when such foreign substances have accumulated in the indicator, they may be blown out at any time, and the interior of the indicator left perfectly clean and free.

The' device by which these important objects are attained can at other times be employed conveniently as a try-cock. v

In the drawings, Bindicates the boiler-head, and A is the tube, attached to it at low-water mark, by which my improved indicator is supported, and through which steam or hot water, as the case may he, passes from the boiler to the indicator.

, C is the body of the indicator, the upper end or cap of which is provided with one or more fusible plugs,

a a, which will be melted by superheated steam and blown out, thereby indicating the dangerous condition of.

the boiler at any time when thewater is too low. Just below the cap, 0, of the indicator, is a corrugated or grooved valve-scat, s, against which seats a plug-valve, a, which is supported and moved by a vertical valvestem, '1, operated by a hand-wheel, to, at the bottom of the apparatus. The valve rests loosely on the top of the stem, and can be rotated upon it, so that it will accommodate itself perfectly to the valve-seat, and so that, when seated, it can be screwed against its seat with any degree of force without rotating with the stem, and thereby grinding its seat, and destroying the packing or facing I, of rubber, cloth, wood, orother suitable substance, provided to insure a perfectly steam-tight joint at that point.

As thus far described, I claim nothing new in my apparatus, for the same general principle believed to have been shown in other devices, although the arrangement and particular construction of the several parts of mine are undoubtedly superior in practical operation to any heretofore brought into use.

The main feature of my invention consists in a peculiar device for destroying or preventing the depositof,

the sediment and scale which have always collected inside of the indicator, arourid and above the valve or stopcock, and cven'on the surface of the .fusible plug, sometimes to such a degree as to stop up the passages, and entirely prevent the steam or hot water from reaching the plug, to destroy it, incase of danger. A thin coating of such scale upon the .fusible plug itself will act as a non-conductorof heat to such an extent as to entirely prevent the plugfrom melting, and to destroy its usefulness, rendering it a source of great danger rather than a means of safety; Nothing effectual has ever been devised for the prevention of these injurious resultsfbut by simply providing a blow-off cock, M, having a stop-cock, m, at the lower part of the indicator, nearly opposite to the end of the main pipe A, the ivhole dimculty is completely obviated. At any time when the sediment -or scale :accumulates in the body of the indicator,'by simply opening the cock m, a current of steam or hot water will be forced from the cock or spout M with great violence, creating a vacuum'in the upper part of the indicator, above the confluence of pipes A O M, which sucks the deposit from the indicator, and discharges it from the spout M.

Thedevice has been very thoroughly tested, and is found to clear the pipes, valves, plugs, and the body of the indicator, in an exceedingly short time.

When not in use for such purpose, the cock in may be cmployedas a try-cock, dispensing with the necessity for an independent cock for. that purpose.

I am aware that a gauge-cool: and alarm-whistle have been heretofore constructed in one instrument, but this I do not claim.

What I (10 claim as my invention, and desire to secure 'by Letters Patent, is The arrangement of the horizontal pipes A, vertical pipes C, branch-pipe M, stop-cock m, cap, 0, having fusible plugs a a, valve 11, having the loose face-plate I, vertical stem T, and hand-wheel W, substantially as shown and deseribed.

To the above specification of my improvement, I have signed'my hand, this 9th day of May, 1868.

' r V T. G. EISWALD. Witnesses:

NATHAN K. ELLswoR'rn, CHAS A. PETTIT. 

